Switch gpu use easily

I have two nvidia cards without Intel and I want to switch between which is being used on my system with one not being used being in a state where it uses little to no power.

How should I proceed?

As you didn’t give much information:

  1. Shut down
  2. Remove second nVidia
  3. Reinstall your system
  4. Set your monitors up the way you want them
  5. shut down
  6. install the second nVidia and don’t hook it up to anything!
  7. Start system.

There! second card ready for CUDA and not using any power unless you use it to run CUDA.

If you would have given some more information as to what your current config is like, we could have given a less brute method of accomplishing the same.